The CalTopo blog has been pretty quiet over the past year, but not due to a lack of innovation. Rather, we’ve been focused on a top secret project – one that after 18 months of development is finally secret no longer: a phone app. Today marks the release of an open beta test for Android; iOS will hopefully follow before summer.

First, let’s set expectations: the app is still in development, and this is a beta test. There are probably some major bugs related to specific platforms or android versions that we haven’t caught yet, and some obvious functionality is missing, such as the ability to place a marker at your current location. We’re releasing this not because it’s a finished product, but because we’re at the point where we need testing and feedback from a broader audience.

With that said, what does the app offer? I’m going to keep this blog post short and refer you to the Play Store listing, but the short version is that tight integration with caltopo.com provides some amazing benefits even if the app’s functionality isn’t fully fleshed out.

The app is free, and for now the only restricted feature is offline map downloads, which are tied to existing CalTopo plans. Basic accounts get 5GB/yr, which is enough to cover the entire JMT at high resolution (2 meter / pixel or zoom 16) with the USGS, NAIP Imagery, MapBuilder Topo/Hybrid/Overlay, shaded relief and slope angle shading layers. Pro accounts get 30GB/yr, which can cover the PCT with those layers twice over at a moderate resolution (4m/px or zoom 15).

To keep downloads small, some offline layers are computed from others: if you have elevation data, you automatically get slope angle shading, and if you have MapBuilder Topo and NAIP Imagery, you automatically get MapBuilder Hybrid.